The incidence of congestive heart failure (CHF) is increasing worldwide with over one million new cases diagnosed annually. Over the past 30 years, counterpulsation with an intra-aortic balloon pump (IABP) has been widely and successfully used as a short-term treatment for cardiac dysfunction. However, counterpulsation is limited by its location within the descending thoracic aorta to short durations of therapy, typically less than 14 days. To overcome this limitation, Superficial Counterpulsation Research (SCR), Inc. has invented a novel system for extended application of counterpulsation therapy for heart failure. The system consists of a 32-ml counterpulsation device (CPD) that is designed to be implanted via a surface operation in the shoulder area (pacemaker pocket). The CPD, a blood sac, is anastamosed to the subclavian artery. A driver for controlling device inflation/deflation timing carried externally allowing complete patient mobility. Preliminary testing with a first generation prototype driver was conducted in mock circulation system and acute animal experiments to define driver performance characteristics. The driver was then re-designed to reduce size and weight, improve force of counterpulsation delivery, increase response to higher heart rates, and extend device longevity. The CPD driver is in fabrication and ready for in vivo testing. The goal of this Phase I SBIR proposal is to compare the hemodynamic efficacy of the 32-ml CPD system (device and driver) to a 40- ml IABP system (catheter and driver). We will also demonstrate that engineering specifications of the new driver are met. This will be accomplished by completing the following specific aim: Aim-1: To demonstrate the efficacy of a 32-ml CPD driver in reducing ventricular afterload and augmenting diastolic perfusion to the heart and vasculature under a variety of clinically-relevant conditions - hypertension, hypotension, and heart failure. Our hypothesis is that the performance of the CPD system will be similar to a standard clinically-available IABP system. If successful, in Phase II we will conduct driver reliability testing controller reliability testing and chronic in vivo testing to demonstrate the long-term effectiveness of the 32-ml CPD system. SCR, Inc. (Louisville, KY) is developing a novel mechanical device to treat early stage heart failure patients. The device can be implanted using a simple surgical procedure comparable to a pacemaker. Since comparable devices can only provide up to 2 weeks of support, SCR is proposing to develop a portable, pneumatic driver to provide up to two years of support. [unreadable] [unreadable] [unreadable]